Switch



Sept. 9 192. 1,508,166

H. J. cRABBs SWITCH WITNESSES:

. I v f NvENToR hie/berief Crab b5 Patented Sept. 9, 1924.

intatte UNrran stares earner oraf-filein,j

vHERBERT J. CRABBs, or rrr'rsnuaen, rENnsYLVANrA, AssIGNon To wnsrine; HOUSE ELECTRIC a MANUFACTURING Coi/riserva, Acolaronerrou' orrnnnsYL- VANIA.

SWITCH.

AppIicaton led May 22, 1920, Serial No. 383,348. Renewed January 31, 1924;

ticularly tosingle or double-throw-knifeblade switches such as are commonly employed on structures for connecting ter.- minals of high-tension circuits. y'

Switches of this type are usually devoid of operating handles and are provided with eyelets or vario-us forms of latches adapted to be engaged by a hook-stick7 or operating rod for moving the switch blade in and out of contact with the jaws.` In Service, such switches are infrequently operated and remain in closed position for long periods of time, during which interval, due to oxidation and corrosion of the` contacting members, the blades becomes fastened within the jaws with such security that it becomes necessary to pry them therefrom by suitable instruments, it being frequently impossible to dislodge them quickly by using the hookstick in the usual manner. In cases of emergency, serious damage may result to machinery, or the life of an operator may be endangered, by reason of the sticking of the blade within the switch aws when itis necessary to quickly open the circuit. i

One object of this invention is to provide a switch where-in the use of a hook-stick in the usual manner Causes the blade first to be positivelypried loose from the jaws by the operating lever, after which loperation the blade may be entire-ly withdrawn from the jaws with little effort..`

Another object is to provide a switch having the above Icharacteristics wherein the latch mechanism employed is of simple, compact and inexpensive construction and wherein vital elements are protected from contact with foreign objects.

Another object is to provide a ,doublethrow switch wherein separate latching levers engage separate latches and wherein the latch levers are counterparts and, therefore, interchangeable.

A further object is to `providea switch latching mechanism employing a minimum number of moving parts, the action of which is positive Vunder severe outdoor conditions.

Afin-ther Objectis to provide aswtch latch designed primarily for double-throw switches, vwhich is inexpensive and maybe used for single-throw` .switches vwithout f necessitatingany change in design.

These -and other objects are attained by means Aof switchapparatus embodying the features herein described andillustrated in the drawingsaccompanying and `forming a part hereof, wherein i Fig. l is a side elevation of the improved switch apparatus, showing thebladein two operative positions. i

Fig. 2 is a plan view Vof the operating levers showing them in assembled relation. Fig. 8 is a side elevation of one of the operating levers showing the inner side thereof, with the position ofthe co-oper'at ing lever indicated indot-and-dashlines.

Referring to the drawing, 'the switchf includes pivot jaw member 5 and two pairs of Contact jaws 6 vand 7, all of which; are supported upon insulated basesor 'f'pedesta'ls 8 which are preferably secured to aI switch base 9. The pivot" clip 5 lis:provided'with a terminal l() which, for the purpose ofillustration, may be considered aswconnected -to a busfbar receiving current from a generator (not shown). The Contact. jaws `6 and 7 are provided with terminals l1 and 12, respectively,which,it will be assumed', are connected to `leads of two separate service circuits. The service 'circuits' are adapted to 'be separately connected to the bus-bar by means of a knifeLswitchiblade'l which` is pivotedto thevpivot` jaw 5 and is adapted to be `swung into operative en-` gagement' with the contact'jawsl 6, as shown in fulllines in Fig. l, or into operativev en-V gagement with the. Contact jaws 7, as' 1nthe bladey in the space between them and hook-stick operated in theus'ual manner.

In order to obviate this difliculty and to apply a posit-ive leverage to the blade sufficient to loosen it from fixed `contact with the jaws, I provide the free end of the blade 13 with a pair of operatimg levers 1li; and 15 which are pivoted on opposite sides of the blade by means of studs 16 and 17, respectively.

The levers ll and 15 are counterparts and, therefore, interchangeable, the former being pivoted, as shown in Fig. 1, on the far side of the blade and the latter upon the near side thereof.

Referring' to Figs. 2 and 3, each lever .includes a side portion 18 having a marginal flange 19 extending entirelv around the periphery thereof and having a section 20 of greater depth than the flange 19 adapted to extend over the end of the switch blade which lies in the space 21 between the flanges 19. The flange portion 20 is provided with a` re-entrant lip or stop 22, which lies adjacent the end 23 (Fig. 1 of the drawing) and is adapted to engage the blade to limit the movement of the lever with respect thereto when the lever is moved to unlatched position during` the opening),` operation of the blade.

The lever is also provided with an inwardly extending lug 24 which engages the end 23 of the blade 13 during the movement of the lever in ther direction tending; to move it into latching' position with al stationary latch member to be hereinafter described.

The lever is provided with a pivot hole 25 vthrough which the pivot studs are inserted in assembling' the lever upon the blade, and the flange 19 is provided with a latch recess 25 havinga latch-engaging,r face or tooth 26 so positioned with respect to the pivot stud that, when the hook 27 is engaged by the hook-stick and the lever 14 is rotated in a clockwise direction, the tooth rotates similarly in a direction away from the end of the switch blade.

Referring to Fig'. 1, each of the jaws 6 and 7 is provided with stationary latch members 28 and 29 which, as shown, are riveted to the jaw base. rFliese latches may be made as integral parts of the jaws and, for the purpose of the claims of this specification, may be considered as parts thereof or as separate stationary latch members. The latch members 2S and 29 are so disposed that they lie in vplanes on opposite sides of the blade and engage the levers leland 15, respectively, when the blade is .moved into the jaws 6 and 7, respectively.

so rounded at 2, adjacent the free end thereof, that it will move over a similarly rounded edge 33 on the co-operating latch member in such manner that the latch lever will be so retracted as to clear the latch member when the blade 13 is moved into operative relation with the contact jaws.

The latch or operating levers l-l and 15 are normally held in the position indicated in Fig'. 1 by means of a helical spring 34, one end of which is attached to the flange 2O of one lever, while the other end is attached to a similar flange on the other member. The spring` lies within the space between the levers and is protected against contact with external or foreign objects by the housing formed by the OjJeiatingl levers. The spring` constantly exerts a force tending,` to draw the lever hooks toward one another and their range of movement, in the direction in which the spring tends to draw them, is limited by means of lugs 24C which engage the end 23 of the blade 13.

It will be seen from the foregoing that, if a hook-Stich were inserted in the hooi; 2T of the lever lll and drawn outwardly in a direction tending to withdraw' the blade from the jaws (i, the lever 14 would pivot upon the stud 16 and so move with relation to the blade as to disengage the teeth 81 and 2o of the latch member and lever, respec tively. rlhe niovement of the lever 14, with respect to the blade, limited, however. by contactot' the stop 22 with the end 233 of the blade and, when the stop 22 engages the end of the blade, the pull of the chooksticli 'is transniitted directly to the blade. its the latch lever is withdrawn at the time from the latch member, the blade is automatically released and may be withdrawn from the jaws. but, as has been previously pointed out, the blade frequently becomes so tightly fastened between the jaws thaty a direct pull on the lever 14, that would not injure it, would not be sufficient to start the movement of the blade. I have, therefore, provided each of the levers 14 and l5 with a projection 35 adapted, when the lever is in latched position, to abut the extren'ie end of the latch member with which it co-operates in such n'ianner that, when the lever is pulled in a direction 'tending' to withdraw the blade, the projection 35 will. .fulcriun on the ends of its respective latch member and positively pry the blade outwardly and loosen it from the j aw by force and leverage greater than could possibly be exerted by a direct pull of the hook-stick that would not injure the lever or latch.

It will be seen from the foregoing that, when a blade is stuck within the jaws, the first unlocking movement of the operating leve-rs, relative to the blade, forces the blade loose from the jaws, after which operation, the blade may be withdrawn with ease by pulling on the hook-stick in the proper direction. The levers are normally held in a predetermined relation with respect to the blade by the spring' 34 and automatically snap into latched relation with its co-operating latch member when the blade is moved into operative relation with the jaws.

Vsliile I have shown the latch member as a portion of the jaw structure, it is obvious that it may be mounted in any convenient manner and may be incorporated in the jaw strips, and that the lever could fulcrum upon anystationary member, not necessarily a part of the latch member, which might be joined to the jaws or be independent thereof, without departing from the spirit of my invention.

While I have described and illustrated but one embodiment of my invention, it will be l. A switch comprising a pivot jaw member, two pairs of spaced contact jaws, a

switch blade pivoted to the pivot jaw mem-V ber and adapted to separately engage the said contact jaws, a pair of latch levers pivoted to the free end of the switch blade and on opposite sides thereof, a latch member adjacent each pair of contact jaws and adapted to engage one ofthe said levers to move it into latching position when the blade is moved into operative relation with the jaws, and a spring connecting the latch levers and adapted to maintain them in yielding operative relation with respect to the latch members, the said levers being so formed as to provide a protecting housing for the spring.

2. In an electric switch, the combination ary contact member and a latch member,y ofv a pair of oppositely disposed operating 4 levers for the movable contact member movably mounted thereon and adapted to cooperate with the latch member, for holding the vsaid contact members in engagement with one another', andl a spring adapted `to normally maintain one of the operating levers in locked engagement with the latch member, the said operating levers being so formed as to provide a housing( for the spring. v

3. A double-throw switch comprising a pair of spaced stationary contact members,`

a-movable contact member having its one end pivoted int-ermediatelyv of the stationary contact members, a pair of latch members movably mounted on the movable contact member adjacent to its free end,.a stationg ary latch member adjacent to each of the stationary contact members and adapted to engage one of the movable latch members, and a spring adapted to maintain veach of the movable latch members in engagement with `one of the stationary latch members, the

movable latch members being so formed as to .provide a housing for the spring.

4. In an electric switch, the combination with a movable contact memberr and a stationary contactv member', of aV stationary latch member, apair of oppositely disposed movable latch members adapted to co-operate with the stationary latch member in order to maintain said contact members in operative relation, and a resilient member for maintaining -the latch members in operative relation, the said movable latch members being so formed as to provide a housing for the resilient member. l

In testimony whereof, I have hereunto subscribed my name this 17thl day of May,

HERBERT J. CRABBS. 

